clarify dns_rdataslab_fromrdataset()

there are now two functions for creating an rdataslab from an
rdataset: dns_rdataslab_fromrdataset() creates a full slab (including
space for a slab header), and dns_rdataslab_raw_fromrdataset() creates
a raw slab.

diff --git a/lib/dns/include/dns/rdataslab.h b/lib/dns/include/dns/rdataslab.h
index 64a20cc29e3bb88648ea26f52da49d71cda33373..82f2a426b18d702a779487be1cfdae5654374422 100644 (file)
--- a/lib/dns/include/dns/rdataslab.h
+++ b/lib/dns/include/dns/rdataslab.h
@@ -173,11 +173,17 @@ extern dns_rdatasetmethods_t dns_rdataslab_rdatasetmethods;
 
 isc_result_t
 dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
-                          isc_region_t *region, unsigned int reservelen,
-                          uint32_t limit);
+                          isc_region_t *region, uint32_t limit);
+isc_result_t
+dns_rdataslab_raw_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
+                              isc_region_t *region, uint32_t limit);
 /*%<
- * Slabify a rdataset.  The slab area will be allocated and returned
- * in 'region'.
+ * Allocate space for a slab to hold the data in rdataset, and copy the
+ * data into it.  The resulting slab will be returned in 'region'.
+ *
+ * The dns_rdataslab_raw_fromrdataset() function allocates and fills only
+ * the memory needed for a raw slab. dns_rdataslab_fromrdataset() also
+ * allocates space for a dns_slabheader object.
  *
  * Requires:
  *\li  'rdataset' is valid.

diff --git a/lib/dns/qpcache.c b/lib/dns/qpcache.c
index 8428451a215a8cf365058ba1f2f1c2bb70d57d07..b25bf45b6e1a5feb40cbcbf8419f9a0d18230d17 100644 (file)
--- a/lib/dns/qpcache.c
+++ b/lib/dns/qpcache.c
@@ -3090,12 +3090,13 @@ addnoqname(isc_mem_t *mctx, dns_slabheader_t *newheader, uint32_t maxrrperset,
        result = dns_rdataset_getnoqname(rdataset, &name, &neg, &negsig);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
-       result = dns_rdataslab_fromrdataset(&neg, mctx, &r1, 0, maxrrperset);
+       result = dns_rdataslab_raw_fromrdataset(&neg, mctx, &r1, maxrrperset);
        if (result != ISC_R_SUCCESS) {
                goto cleanup;
        }
 
-       result = dns_rdataslab_fromrdataset(&negsig, mctx, &r2, 0, maxrrperset);
+       result = dns_rdataslab_raw_fromrdataset(&negsig, mctx, &r2,
+                                               maxrrperset);
        if (result != ISC_R_SUCCESS) {
                goto cleanup;
        }
@@ -3129,12 +3130,13 @@ addclosest(isc_mem_t *mctx, dns_slabheader_t *newheader, uint32_t maxrrperset,
        result = dns_rdataset_getclosest(rdataset, &name, &neg, &negsig);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
-       result = dns_rdataslab_fromrdataset(&neg, mctx, &r1, 0, maxrrperset);
+       result = dns_rdataslab_raw_fromrdataset(&neg, mctx, &r1, maxrrperset);
        if (result != ISC_R_SUCCESS) {
                goto cleanup;
        }
 
-       result = dns_rdataslab_fromrdataset(&negsig, mctx, &r2, 0, maxrrperset);
+       result = dns_rdataslab_raw_fromrdataset(&negsig, mctx, &r2,
+                                               maxrrperset);
        if (result != ISC_R_SUCCESS) {
                goto cleanup;
        }
@@ -3184,8 +3186,7 @@ qpcache_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
        REQUIRE(version == NULL);
 
        result = dns_rdataslab_fromrdataset(rdataset, qpdb->common.mctx,
-                                           &region, sizeof(dns_slabheader_t),
-                                           qpdb->maxrrperset);
+                                           &region, qpdb->maxrrperset);
        if (result != ISC_R_SUCCESS) {
                if (result == DNS_R_TOOMANYRECORDS) {
                        dns__db_logtoomanyrecords((dns_db_t *)qpdb,

diff --git a/lib/dns/qpzone.c b/lib/dns/qpzone.c
index 067fc8711e09ae228a49b6f422c2348c2c89fdf0..db5f6a0727ef76ad19a94ba4f7d0bc0b9c9a6e0f 100644 (file)
--- a/lib/dns/qpzone.c
+++ b/lib/dns/qpzone.c
@@ -2241,8 +2241,7 @@ loading_addrdataset(void *arg, const dns_name_t *name,
 
        loading_addnode(loadctx, name, rdataset->type, rdataset->covers, &node);
        result = dns_rdataslab_fromrdataset(rdataset, qpdb->common.mctx,
-                                           &region, sizeof(dns_slabheader_t),
-                                           qpdb->maxrrperset);
+                                           &region, qpdb->maxrrperset);
        if (result != ISC_R_SUCCESS) {
                if (result == DNS_R_TOOMANYRECORDS) {
                        dns__db_logtoomanyrecords((dns_db_t *)qpdb, name,
@@ -4724,8 +4723,7 @@ qpzone_addrdataset(dns_db_t *db, dns_dbnode_t *dbnode,
                 rdataset->covers != dns_rdatatype_nsec3));
 
        result = dns_rdataslab_fromrdataset(rdataset, qpdb->common.mctx,
-                                           &region, sizeof(dns_slabheader_t),
-                                           qpdb->maxrrperset);
+                                           &region, qpdb->maxrrperset);
        if (result != ISC_R_SUCCESS) {
                if (result == DNS_R_TOOMANYRECORDS) {
                        dns__db_logtoomanyrecords((dns_db_t *)qpdb, &node->name,
@@ -4854,8 +4852,7 @@ qpzone_subtractrdataset(dns_db_t *db, dns_dbnode_t *dbnode,
 
        dns_name_copy(&node->name, nodename);
        result = dns_rdataslab_fromrdataset(rdataset, qpdb->common.mctx,
-                                           &region, sizeof(dns_slabheader_t),
-                                           0);
+                                           &region, 0);
        if (result != ISC_R_SUCCESS) {
                return result;
        }

diff --git a/lib/dns/rdataslab.c b/lib/dns/rdataslab.c
index 42fe27fcb9dedd5169ca0926b4a7a5dd7ff1dfb5..143059140515be76f326ae09f0de48425127300b 100644 (file)
--- a/lib/dns/rdataslab.c
+++ b/lib/dns/rdataslab.c
@@ -47,7 +47,7 @@
  * The rdataslab structure allows iteration to occur in both load order
  * and DNSSEC order.  The structure is as follows:
  *
- *     header          (reservelen bytes)
+ *     header          (dns_slabheader_t)
  *     record count    (2 bytes)
  *     offset table    (4 x record count bytes in load order)
  *     data records
@@ -56,6 +56,8 @@
  *             meta data       (1 byte for RRSIG's)
  *             data            (data length bytes)
  *
+ * A "raw" rdataslab is the same but without the header.
+ *
  * DNSSEC order traversal is performed by walking the data records.
  *
  * The order is stored with record to allow for efficient reconstruction
@@ -118,10 +120,9 @@ compare_rdata(const void *p1, const void *p2) {
        return dns_rdata_compare(p1, p2);
 }
 
-isc_result_t
-dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
-                          isc_region_t *region, unsigned int reservelen,
-                          uint32_t maxrrperset) {
+static isc_result_t
+makeslab(dns_rdataset_t *rdataset, isc_mem_t *mctx, isc_region_t *region,
+        uint32_t maxrrperset, bool raw) {
        /*
         * Use &removed as a sentinel pointer for duplicate
         * rdata as rdata.data == NULL is valid.
@@ -129,6 +130,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
        static unsigned char removed;
        dns_rdata_t *rdata = NULL;
        unsigned char *rawbuf = NULL;
+       unsigned int headerlen = raw ? 0 : sizeof(dns_slabheader_t);
        unsigned int buflen;
        isc_result_t result;
        unsigned int nitems;
@@ -136,7 +138,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
        unsigned int length;
        unsigned int i;
 
-       buflen = reservelen + 2;
+       buflen = headerlen + 2;
 
        nitems = dns_rdataset_count(rdataset);
 
@@ -151,7 +153,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
                rawbuf = isc_mem_get(mctx, buflen);
                region->base = rawbuf;
                region->length = buflen;
-               rawbuf += reservelen;
+               rawbuf += headerlen;
                *rawbuf++ = 0;
                *rawbuf = 0;
                return ISC_R_SUCCESS;
@@ -231,6 +233,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
         * Don't forget the last item!
         */
        buflen += (2 + rdata[i - 1].length);
+
        /*
         * Provide space to store the per RR meta data.
         */
@@ -259,7 +262,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
        region->base = rawbuf;
        region->length = buflen;
 
-       rawbuf += reservelen;
+       rawbuf += headerlen;
 
        put_uint16(rawbuf, nitems);
 
@@ -272,6 +275,7 @@ dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
                        length++;
                }
                INSIST(length <= 0xffff);
+
                put_uint16(rawbuf, length);
 
                /*
@@ -295,6 +299,18 @@ free_rdatas:
        return result;
 }
 
+isc_result_t
+dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
+                          isc_region_t *region, uint32_t maxrrperset) {
+       return makeslab(rdataset, mctx, region, maxrrperset, false);
+}
+
+isc_result_t
+dns_rdataslab_raw_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
+                              isc_region_t *region, uint32_t maxrrperset) {
+       return makeslab(rdataset, mctx, region, maxrrperset, true);
+}
+
 unsigned int
 dns_rdataslab_sizeraw(unsigned char *slab) {
        REQUIRE(slab != NULL);